Corner beads are well known. A typical corner bead is made of metal and takes the form of opposed elongated side flanges extending laterally from each side of an elongated central bead which forms a reference from which a filling compound such as plaster may be trowelled to cover the side flanges. Such corner beads are normally applied by positioning the back face of the corner bead against the panels forming the corner and attaching the flanges to the wall. Typically this is achieved by utilising either of two main attachment methods, and then finishing/securing with the use of filling compound to finish the joint.
The first attachment method uses nails to attach the flanges to the wall and the second attachment method uses paper tape and the filling compound to attach the flanges to the wall.
One known corner bead which is disclosed in U.S. Pat. No. 2,643,423 describes a metal corner bead for an external wall junction. The corner bead flanges are provided with perforations to receive nails for securing the flanges to the wall. Additionally, a separate strip of perforated flexible tape spans over the outer face of each flange and the joint between the outer edge of each flange and the wall, and the flexible tape is secured in position by filling compound.
Another known corner bead which is disclosed in U.S. Pat. No. 2,904,856 also discloses a metal corner bead for an external wall junction in which the flanges are also provided with perforations. Additionally, a separate L-shaped strip of perforated paper, which extends beyond the flange outer edges, is sandwiched between the inner face of the corner bead and the wall. The components are positioned so that the perforations in the corner bead register with the perforations in the paper and are of sufficient size to receive filling compound thus forming binding posts to anchor the flanges to the wall.
There are a number of problems of prior art corner beads and their application or fixing to wall components. These problems relate to:
the amount of time taken and the degree of skill required to apply the corner beads; PA1 the visual appearance of the corner beads after finishing; PA1 the poor adhesion and thus lack of strength. For example, poor adhesion between metal or plastics and plaster components; PA1 protruding jointing compound in the vicinity of the perforations; PA1 the covering of the nail heads; PA1 the damage to the paper where a paper layer extends over the outer face of the bead portion of the corner bead, and PA1 the exposure of metal flange parts which can result in cracking. PA1 an elongate body structure providing an elongate reference bead assembly providing a reference face or opposed reference faces and a respective offset flange extending from each of the opposite sides of said reference bead assembly and offset rearwardly from the reference face or a respective one of said reference faces; PA1 a back layer of flexible material substantially covering the back face of said elongate body structure, and PA1 respective front layers of flexible material substantially covering the front face of each said flange and terminating at their inner edges near adjacent ones of said opposite sides. PA1 an elongate body structure providing an finishing edge having a reference face extending therealong; PA1 an offset flange extending from the elongate body structure opposite said finishing edge and offset rearwardly from the reference face; PA1 a back layer of flexible material substantially covering the back faces of said elongate body structure and said offset flange, and PA1 a front layer of flexible material substantially covering the front face of said offset flange and terminating adjacent reference face. PA1 applying a filling compound to the rear face of the corner bead assembly and/or the front wall panel surfaces at the joint; PA1 operatively locating the rear face of the corner against the front wall surfaces at the joint to adhere the corner bead in position with close adherence of the outer edges of the corner bead assembly to the overlapped wall panel surfaces, and PA1 trowelling a filling layer of filling compound over the opposed flanges using the exposed metal or plastics reference face or a respective one of said reference faces as a guide for the trowel or scraper.
It is an object of this invention to alleviate at least one of the above disadvantages and/or to provide a useful alternative to known corner beads and their method of application, which will be reliable and efficient in use.